PTGER1 and cancer: Subsequently, UALCAN-based OS analysis revealed that elevated PTGER1 expression was significantly associated with poor survival in eight cancer types: head and neck squamous carcinoma (HNSC) (p = 0.032), KIRC (p < 0.0001), kidney renal papillary cell carcinoma (KIRP) (p = 0.043), LGG (p = 0.029), LUSC (p = 0.048), mesothelioma (MESO) (p = 0.00031), UCEC (p = 0.00045), and UVM (p < 0.0001).